ExxonMobil would like a carbon tax. Barack Obama would not.

Exxon Mobil Corp. is part of a growing coalition backing a carbon tax as an alternative to costly regulation, giving newfound prominence to an idea once anathema in Washington. …

“Combined with further advances in energy efficiency and new technologies spurred by market innovation, a well-designed carbon tax could play a significant role in addressing the challenge of rising emissions,” Kimberly Brasington, a spokeswoman for the company, said in an e-mail. “A carbon tax should be made revenue neutral via tax offsets in other areas,” she added.

Exxon’s political action committee gave nearly $1.2 million to political candidates in the past two years, 93 percent of it to Republicans, according to the Center for Responsive Politics.